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GNSS gyroscopes:determination of angular velocity and acceleration with very high-rate GNSS

Satellite Navigation 2024年第1期5卷 74-90页

作者： Yun Shi Peiliang Xu Yuanming Shu Xiaolin Meng School of Geomatics Xi’an University of Science and TechnologyXi’an710054People’s Republic of China Disaster Prevention Research Institute Kyoto UniversityUjiKyoto611-0011Japan College of Marine Geosciences Ocean University of ChinaQingdaoPeople’s Republic of China School of Instrument Science and Engineering Southeast UniversityNanjing210096People’s Republic of China

Although global navigation satellite systems(GNSS)have been routinely applied to determine attitudes,there exists no literature on determining angular velocity and/or angular acceleration from *** by the invention of computerized accelerometers of the correspondence author and following the success of accurately recovering translational velocity and acceleration waveforms from very high-rate GNSS precise positioning by Xu and his collaborators in 2021,we propose the concept of GNSS gyroscopes and reconstruct angular velocity and acceleration from very high-rate GNSS attitudes by applying regularization under the criterion of minimum mean squared *** major results from the experiments can be summarized in the following:(i)angular velocity and acceleration waveforms computed by applying the difference methods to high-rate GNSS attitudes are too noisy and can be physically not meaningful and numerically *** same can be said about inertial measurement unit(IMU)attitudes,if IMU gyros are not of very high accuracy;(ii)regularization is successfully applied to reconstruct the high-rate angular velocity and acceleration waveforms from 50 Hz GNSS attitudes and significantly outperforms the difference methods,validating the proposed concept of GNSS *** comparing the angular velocity and acceleration results by using the difference methods and regularization,we find that the peak values of angular velocity and acceleration by regularization are much smaller by a maximum factor of 1.57 in the angular velocity to a maximum factor of 8662.53 times in the angular acceleration in the case of high-rate GNSS,and by a maximum factor of 1.26 in the angular velocity to a maximum factor of 2819.85 times in the angular acceleration in the case of IMU,respectively;and(iii)the IMU attitudes apparently lead to better regularized angular velocity and acceleration waveforms than the high-rate GNSS attitudes,which can well be explained by the fact that the

关键词： angular velocity angular acceleration High-rate GNSS GNSS attitudes GNSS gyroscopes Regularization

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Road identification method based on angular acceleration of vehicle driving wheel

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Journal of Beijing Institute of Technology 2012年第4期21卷 466-471页

作者：李福庆刘昭度 School of Mechanical Engineering Beijing Institute of Technology

The fundamental principle of road identification by using angular acceleration of driving wheels was demonstrated in this paper. Based on the analysis of energy conversion and parameters variation during the vehicle drive slip process, the change of adhesion coefficient relative to the an- gular acceleration were theoretically studied experimentally validated. The variation shows that the change of adhesion coefficient relative to the angular acceleration and the change of slip ratio in the drive slip process have same trend-both of them exist an only optimal angular acceleration corre- sponding to the peak value of adhesion coefficient. The peak adhesion coefficient of the prototype vehicle is about 0. 14 on the ice-covered road surfaces, with the corresponding optimal angular accel- eration of about 23.5 rad/s2 and optimal slip ratio of about 9. 4%.

关键词： road surface identification adhesion coefficient angular acceleration slip ratio

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Quantitative analysis of the protective performance of bicycle helmet with multidirection impact protection system in oblique impact tests

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Chinese Journal of Traumatology 2024年第4期27卷 226-234页

作者： Yong Han Hao Yang He Wu Di Pan Bing-Yu Wang School of Mechanical and Automotive Engineering Xiamen University of TechnologyXiamen361024Fujian provinceChina Fujian Key Laboratory of Bus Advanced Design and Manufacturing Xiamen361024Fujian provinceChina School of Aerospace Engineering Xiamen UniversityXiamen361005Fujian provinceChina

Purpose:The current study aimed to assess the protective performance of helmets equipped with multidirectional impact protection system(MIPS)under various oblique impact ***:Initially,a finite element model of a bicycle helmet with MIPS was developed based on thescanned geometric parameters of an actual bicycle ***,the validity of model wasconfirmed using the KASK WG11 oblique impact test *** different impact angles(30°,45°,and 60°)and 2 varying impact speeds(5 m/s and 8 m/s)were employed in oblique tests to evaluateprotective performance of MIPS in helmets,focusing on injury assessment parameters such as peaklinear acceleration(PLA)and peak angular acceleration(PAA)of the ***:The results demonstrated that in all impact simulations,both assessment parameters werelower during impact for helmets equipped with MIPS compared to those *** PAA wasconsistently lower in the MIPS helmet group,whereas the difference in PLA was not significant in the noMIPS helmet *** instance,at an impact velocity of 8 m/s and a 30°inclined anvil,the MIPS helmetgroup exhibited a PAA of 3225 rad/s^(2) and a PLA of 281 *** contrast,the no-MIPS helmet group displayeda PAA of 8243 rad/s^(2) and a PLA of 292 ***,both PAA and PLA parameters decreased with theincrease of anvil *** a 60°anvil angles,PAA and PLA values were 664 rad/s^(2) and 20.7 g,respectively,reaching their ***:The findings indicated that helmets incorporating MIPS offer enhanced protection againstvarious oblique impact *** assessing helmets for oblique impacts,the utilization of larger angleanvils and rear impacts might not adequately evaluate protective performance during an impact *** findings will guide advancements in helmet design and the refinement of oblique impact testprotocols.

关键词： Oblique impact Multi-direction impact protection system WG11 oblique impact test angular acceleration

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Theoretical and Practical Studies of Determining the Force of the Lifting-Lowering of the Roll Box

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Engineering（科研） 2023年第1期15卷 47-57页

作者： Usmonov Shuxratjon Kamoljonovich Namangan Institute of Engeenering and Technology Namangan Uzbekistan

The lifting and lowering mechanism of the roll box of the saw gin, being an integral part of the ginning process, is used when starting the electric motor of the saw cylinder until its rated speed is reached to prevent an increase in the load current on it, as well as to start the ginning process. The article defines the kinematics of the movement, and also studies the regularity of the movement of the roll box of the saw gin when lifting it with the help of a pneumatic drive. The kinematics of the roll box movement was determined through experimental studies. Knowing the equation of motion, using the second-order Lagrange equation, the regularity of the change in the lifting force of the roll box was determined. Here the system is closed, its degree of freedom is equal to one. The angle of rotation of the roll box is taken as a generalized coordinate. Numerical results were obtained using the Matlab software environment. The theoretical analysis and graphs for determining the lifting force of the roll box are presented. To study the kinematics of lifting the roll box, a method and a test bench have been developed. According to him, when the roll box was raised, its movement was recorded on video, the image was processed using the After Effect and CorelDraw programs, and the movement of the rod attachment point to the roll box was determined. And also the equation for changing the angle of rotation of the roll box is determined using the Matlab Curve Fiting program.

关键词： Saw Gin Roll Box Pneumatic Cylinder Rod angular Velocity angular acceleration Gravity Forces Driving Force Moment of Inertia Function

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Numerical Simulation of the Transient Flow in a Centrifugal Pump during Regulating Period

Numerical Simulation of the Transient Flow in a Centrifugal ...

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2011 International Conference on Advanced Materials and Information Technology Processing(AMITP 2011)

作者： Yue Tang Erhui Liu Lingdi Tang Wang Hui Research Center of Fluid Machinery Engineering and Technology Jiangsu University

Centrifugal pump performance has transient effect obviously during rapid changing period and the pump hydrodynamic performance of transient is different from steady-state process. In order to research

ISBN: (纸本)9783037851555

关键词： Centrifugal pump Dynamic mesh technology Transient Numerical method angular acceleration moving boundary fluid flow pressure change STREAMS(PROCESS) mesh method Pumps UHF Direction Finder Transient flow Transient performance numerical simulation CENTRIFUGAL PUMP

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